When you have many options to do the same work, you need to choose the best option with least cost and more benefit.
Let’s say you have three different ways to build your application and for each build you will choose different resources to do the work.You want to choose the build that is cost effective. Let’s say the cost rate of the five resources is as shown below
You have sequenced your tasks as Design, Build and Test.
Now, try different build options you need to change the duration, work and resource assign of Build task every time. A better option is use to have three build tasks with different duration, work and resource estimates
If you want to try with Build 1 estimates, select Build 2 and Build 3 tasks and inactivate them.
You will now notice that Build 2 and Build 3 will no longer affect the schedule and the resource availability, this can help you to total estimate with Build 1 as the option. Now, you can try to activate and inactivate the other two tasks to know the best option.
Inactivate tasks is available since Project 2010. Don’t delete the task rather preserve it for future reference